A common type of cellular communications system employs one or more Mobile Switching Centers (MSC) connected to multiple base stations. An MSC typically includes a control complex and at least one switch which interfaces with the Public Switched Telephone Network (PSTN) and with other networks, allowing calls to flow between these networks and the cellular system. The control complex performs a variety of functions, including mobility management functions necessary to route calls to and from specific base stations, through which cellular phone users gain access to the cellular system.
A problem with cellular system designs like that just described is that each base station must be equipped with its own set of radio transceivers to provide access to cellular phone users operating within the base station's boundaries, commonly referred to as a cell. This presents a problem in that each base station must be equipped with enough radios to support a high demand for system access during peak times. When the demand for access diminishes during off-peak times, which can account for the greater part of the day, many of the radios in the base station can become idle, an expensive waste of resources. Thus, a problem with current art is that service providers must outlay substantial capital to equip their systems with a relatively high number of radios, many of which are underutilized throughout much of the day.
Contributing to this problem is the inherent inability of existing system designs to allow the sharing of idle radios across the network of base stations, so that base stations in temporary need of more radios can “borrow” from base stations having a temporary surplus. For example, cells located along inner city expressways might experience peak traffic during rush hours on weekdays, but relatively little traffic on weekends. Other cells located near a sport stadium might experience peak traffic during games on the weekends, but relatively little traffic during the weekdays. With current cellular system designs, radios available at base stations near the sports stadium can not be used to help meet rush hour demands at base stations along the expressway. Similarly, base stations near the sports stadium, straining to meet access demands during a weekend game, receive no help from idle radios located at the base stations in the inner city. Therefore, a need exists for a cellular communication system that allows its radio resources to be shifted to different base stations, when needed, to support system-wide traffic needs as the demand for access fluctuates from cell to cell throughout the day.